inaugural vs inauguration

inaugural

noun
  • An inauguration; a formal beginning. 

  • A formal speech given at the beginning of an office. 

adj
  • Of inauguration; as in a speech or lecture by the person being inaugurated. 

  • Marking the beginning of an operation, venture, etc. 

inauguration

noun
  • The formal beginning or initiation of any movement, enterprise, event etc. 

  • The act of inaugurating, or inducting into office with solemnity; investiture by appropriate ceremonies. 

How often have the words inaugural and inauguration occurred in a corpus of books? (source: Google Ngram Viewer )